Synchronization system for a controlled operation on a moving web

ABSTRACT

An operational function, such as the exposure of a photographic image, is performed on a continuously moving web, such as a photosensitive paper, so that the operations are synchronized to act on predetermined portions of the web. The timing of the operations with respect to the positional orientation of the predetermined web portions may be adjustably varied to achieve precise registration without stopping the web. This may be accomplished by providing an electrical pulse indicating that a predetermined web portion is approximately registered in a station wherein the operation is to be performed, providing a train of electrical pulses having a frequency which is synchronized with the speed of the web through the station, providing an actuating signal for effecting the operation on the occurrence of both a pulse of the pulse train and the firstmentioned pulse in a predetermined relation to each other, and adjustably varying the phase of the pulse train with respect to the passage of the predetermined portion of the web through the station so that the occurrence of the actuating signal may be synchronized with the instant that the predetermined web portion is in precise registration therein.

United States Patent [72] Inventor Charles Harry Dietz San Diego, Calif.

[2]) App]. No. 780,671

[22] Filed Dec. 3, I968 [45] Patented Aug. 31, I971 {73] Assignee Stromberg Datagraphics, Inc. v

San Diego, Calif.

[54] SYNCHRONIZATION SYSTEM FOR A CONTROLLED OPERATION ON A MOVING WEB 25 Claims, 12 Drawing Figs.

52 us. 01 ass/14, 355/16, 355/64, 355/1 11 [51] Int. Cl G031) 15/05, G03b 27/46, G031) 27/10 [50] Field ofsearch 355/14, 16, 17, 64, 31, 111; 352/16-21 [56] 7 References Cited I UNITED STATES PATENTS 2,552,255 5/1951 Capstaff 355/111 2,943,554 6/1960 K'zistner 355/1 11 X 3,385,161 5/1968 Sage et al 355/5 X 3,441,342 4/1969 Ball et a1 352/17 3,450,473 6/1969 Hunstiger 355/4 T0 STROE a FILM TRANSMT CONTROL LOGIC 3,495,903 2/1970 Morley et al Primary ExaminerSamuel S. Matthews Assisran! Examiner-Michael D. Harris A!torney-Anderson, Luedeka, Fitch, Even and Tabin ABSTRACT; An operational function, such as the exposure of a photographic image, is performed on a continuously moving web, such as a photosensitive paper, so that the operations are synchronized to act on predetermined portions of the web. The timing of the operations with respect to the positional orientation of the predetermined web portions may be adjustably varied to achieve precise registration without stopping the web. This may be accomplished by providing an electrical pulse indicating that a predetermined web portion is approximately registered in a station wherein the operation is to be performed, providing a train of electrical pulses having a frequency which is synchronized with the speed of the web through the station, providing an actuating signal for effecting the operation on the occurrence of both a pulse of the pulse train and the first-mentioned pulse in a predetermined relation to each other, and adjustably varying the phase of the pulse train with respect to the passage of the predetermined portion of the web through the station so that the occurrence of the actuating signal may be synchronized with the instant that the predetermined web portion is in precise registration therein.

PATENTED M1831 I97: 3.602.589

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INVENTOR CHARLES H DIETZ 553m q mwl mom 0mm SYNCHRONIZATION SYSTEM FOR A CONTROLLED OPERATION ON A MOVING WEB The present invention relates to a method and apparatus for synchronizing the action of a functional operation on a moving web with respect to a predetermined portion thereof which moves into registration to receive said operation, and particularly to the synchronization of photographic image exposures on predetermined or form portions of a continuously moving photosensitive medium. More particularly, an embodiment of the present invention is herein illustrated and described in connection with a high-speed printer for making enlarged copies of such photographic images on a photosensitive web .from unperforated microfilm strip utilizing an electrophotographic process.

While general data and information storage techniques employing microsized photographic data, such as microfilm, are now well known, the practical use of such techniques inherently presents certain difficulties in the retrieval and reproduction of the data, as well as in the provision for data output in a form convenient and well adapted for its intended eventual use. Where there are large volumes of data to be retrieved and reproduced into a more convenient form for handling, such as by conversion to some form of hard copy or paper output, it is desirable that printing apparatus for this purpose be capable. of operation at extremely high speed, while providing consistent high-quality image reproduction.

Such microfilm data storage techniques may, for example, be used for maintaining a record of customer accounts in the operation of a business concern. Each customer account may be contained on one or more frames of a microfilm reel or reels. When desired, such as for producing monthly billings, etc., each account may be printed out on paper copy, showing the transactions of each account for that billing period, and the paper copies may then be mailed directly to each respective customer. Where the number of customers involved is great, expeditious and economical handling requires that the microfilm be printed out at a very rapid rate while maintaining legibility and controlled correspondence or registration between themicrofilm image and the output copy paper.

In certain applications it is desirable to employ a paper which is preprinted with letterheads, invoice forms, or other fixed information, and to add the variable information from the microfilm thereto so as to fill in the appropriate blanks in the preprinted forms. Various types of apparatus have heretofore been proposed for printing data on preprinted forms by using a line-by-line intermittent paper-feeding operation, but these necessarily result in printing speeds which are less than optimum because of the required stopping and starting of the paper. In the employment of a continuously moving paper web, as hereinafter described, greater printing speeds may be attained with apparatus of relatively less complexity, but proper registration of the data to be printed and the paper FIG. 5 is a perspective view of the exposure station of the apparatus of FIG. 1;

forms may be critical. This is especially so where the forms contain preprinted fixed data to which the variable printed data is to be registered.

Accordingly, it is an object of the present invention to provide an improved method and apparatus for registering predetermined portions of a high-speed continuously moving web with respect to a given position to receive a functional operation. such as a printing operation, thereon.

' It is another object of the invention to provide a method and apparatus for providing synchronization ofimage exposure on predetermined form portions or sections of a continuously moving photosensitive web.

It is a further object of the present invention to provide improved printing apparatus having the capability of printing variable data from microfilm strip onto blank or preprinted forms with precise registration of the variable with the fixed data, and at high-speed operation.

Other objects and advantages of the present invention will be apparent from the following detailed description when con- FIG. 6 is a schematic illustration of the light source and optical arrangement employed in the apparatus of FIG. 1;

FIG. 7 is a perspective view showing the upper paper transport assembly and paper registration controls employed in the apparatus of FIG. 1;

FIG. 8 is a more or less diagrammatic view in elevation of the mechanism of the paper registration controls shown in FIG. 5;

FIG. 9 is a partial view in section taken along line 9-9 of FIG. 8 in the direction of the arrows;

FIG. 10 is an elevational view of a segment of program tape which may be-advantageously employed in the paper registration controls of the apparatus of FIG. 1; and

FIGS. 11 and 12 are schematic diagrams showing logic circuits which may be employed in the apparatus of FIG. 1.

In general, referring to FIG. 1, apparatus is provided for printing images from a photographic film medium, such as reel-type microfilm 10, onto a photosensitive or electrophotographic hard copy medium, such as zinc-oxidecoated paper 12, at high speed by means of a fast light source or strobe 14 in an optical assembly 15, and a projection lens 16 which projects enlarged images from the microfilm 10 to the paper 12 at an exposure station 18. An electrostatic processing system sensitizes the paper prior to exposure and then develops and dries the enlarged images thereon. A hard copy or paper transport means, generally indicated as 20, is provided for continuously moving the electrophotographic medium, in continuous web form, through the exposure station 18 at constant speed. The light source and optical assembly 15, comprising the strobe-type flash lamp 14, projects a short duration or fast image from the film medium to cause exposure thereof on the moving electrophotographic medium 12 at the exposure station 18. A film transport means 24 is also provided for moving the film medium 10 intermittently from one image to another, so that the exposed film image is maintained stationary during the exposure on the continuously moving paper web, the'film 10 being moved rapidly from one image position or frame to another while the lamp 14 is off. The registration of each projected image in the exposure station 18 is detected by a registration photosensor 26 in a manner to be hereinafter described.

The electrophotographic paper 12 may be fan-folded, as shown, with transverse perforations or weakened regions at each of the folds to permit easy detachment of the paper into individual or discrete segments or forms. These folds and perforations thus define a plurality of predetermined portions or sections of the paper medium which are each placed in registration to receive the projected image or images from the microfilm, and each of these portions of the paper may, if desired, have a preprinted form or letter format thereon; alternatively, these portions of the paper may merely be blank. When the preprinted forms are of small size, two or more forms may be placed in the segment between adjacent folds.

A hard copy or paper registration control means 28 is provided for synchronously actuating or flashing the strobe 14 in normal operation only when such'a predetermined portion or form of the moving electrophotographic paper 12 is registered or aligned in the exposure station 18 to properly receive the projected stationary image from the microfilm 10. The paper web 12 preferably has marginal sprocket holes 27a, 2712 (FIG.

5) along each edge by which the paper transport means 20 moves the paper in synchronism with the mechanical rotational components thereof through sprocket or pinwheel assemblies 29, 30 and 31, which engage the sprocket holes in the paper. The registration control means 28 is responsive to the positional orientation of the paper transport by means of a mechanical coupling thereto, represented by dotted line 32, and to a form registration program input 33, later to be described in detail, which provides the necessary registration information to the system, corresponding to the length (in the direction of travel) of the predetermined'portions or forms on the paper 12, so that the registration control means 28 provides an output signal indication on lead 34 when each form portion is correctly registered in the exposure station. Registration information for various form lengths may be supplied by providing a suitable registration program corresponding to the particular paper form-length used.

Logic means, shown as strobe and film transport control logic 36, is provided which is responsive to the projected image registration detecting'photosensor 26 and to the output of the paper registration control means 28 for flashing the strobe 14 on the occurrence of the registration of a predetermined form-portion of the continuously moving paper 12 in the exposure station 18 while the stationary projected film image is also registered therein.

One or more copies of a microfilm image may be made automatically by means of a multiple copy set and counter circuit 38 which is coupled to the control logic 36. By suitable preselection of the desired number of copies of each microfilm image frame (e.g., by means of a suitable selector switch), the normal film transport operation is disabled until the preselected number of exposures have been completed, each on a successive form portion of the paper 12, after which the film transport 24 moves the microfilm to the next image frame, and so on.

A system or train of carts 40 is provided which travel on suitable tracks, guides or rails 42 and are adapted to'respectively deliver and receive stacks of the fan-folded electrophotographic paper at input and output stations, 44 and 46, respectively, of the apparatus, in a continuous fashion as the printing operation progresses.

According to one aspect of the present invention, and as illustrated in FIG. 2, the paper registration control means 28 comprises coarse registration control means 50 which is responsive to the positional orientation of the transport, which is synchronized with the motion of the web 12, for providing a coarse timing signal output indication on lead 52 when each predetermined portion, section or'form of the web is approximately registered in the exposure station, and a fine registration control means 54 for providing a fine timing signal output on lead 56 having an adjustably variable relationship to the time at which each predetermined web portion is properly positioned in the exposure station. Comparison means, illustrated as combining circuit 58, is responsive to the coarse and fine signal outputs on leads 52 and 56, and provides an output signal on lead 34 for causing the actuation or flashing of the strobe 14 when both the coarse and fine signals occur in a given relation to each other. The occurrence of each output signal is adjusted for correspondence, in time, to the instant at programmed intervals is required to correspond to the length of the predetermined web portions. The programmed lengths are metered by paper transport motion, as indicated by the positional indication input 32 of the transport. A fine registration adjustment 64 permits the relationship of the fine timing signals to the paper position to be varied for achieving precise registration in a manner to be described in greater detail hereinafter.

However, before such description is given, certain features of the illustrated apparatus will be described for the sake of completeness and to facilitate a better understanding of both the broad and the relatively narrower aspects of the present invention. Referring to FIG. 1, the film transport 24 may accept l6-millimeter nonperforated microfilm on standard reels, and having a film format as illustrated in FIG/4. As there shown, registration index marks 66 in the form of optical stripes are disposed along the edge of the film 10 and centered on the optical axis of each image frame 68. The film may, for example, have opaque images on a transparent background in each frame, with transparent optical stripes on an opaque border 70. The film transport 24 has supply and takeup spindles and a film-driving capstan which are each driven by separate servomotors controlled by the strobe and film transport control logic 36, as shown. The control logic 36 may provide various prescribed and controllable modes of operation, including a normal printing mode of operation wherein the film is intermittently advanced at a fast speed from each frame to the next successive frame, but at a predetermined distance from the correct registration of the successive frame, the film speed is reduced to a low value and then stopped for registration of the film image with the permitted tolerance within the film gate and for registration of the projected image within the exposure station. Vacuum buffer columns, each having a suitable loop-sensing device, are respectively provided, as shown, adjacent the supply and takeup reels, the sensing devices being coupled back to the control logic 36 for appropriate reel motor operation.

The projected image actually comprises two principal portions, namely, an informational or data portion 68 to be printed or copied and a registration indexing portion 66, as shown in FIG. 4. The coated paper 12 is positioned in the exposure station (FIG. 5) with a form portion, defined by the spaced lateral perforations 96, 96', etc., equally spaced from respective upper and lower paper exposure masks 98 and 100, and the informational portion 68 of the microfilm image is exposed to the paper 12 between the lateral perforations 96 and 96' and between the marginal sprocket holes 27a and 27b. The lateral perforations 96, 96 are also fold lines, if only one form portion is provided on each web segment.

The film image registration is accomplished by imaging the registration index mark or stripe onto the paper or "image plane (FIG; 1) at the exposure station 18 and detecting the projected image of this mark with registration photosensor 26 and change-speed photosensor 92. Registration photosensor 26 is disposed on the lateral or horizontal axis 94 of the exposure station, and the other photosensor 92 is located below the axis 94 to initiate the slowing of the film in the manner previously described, the projected image being inverted by the lens 16. 7

Referring to FIG. 6, the light source assembly 15 is diagrammatically illustrated to show an arrangement of the principal component parts thereof. Briefly, a beam composed primarily of blue and ultraviolet radiation, emitted by the strobe 14, and a'beam composed primarily of infrared radiation, emitted by infrared lamp 106, are combined by means of a 45 dichroic mirror 108 which is transparent to red and infrared and reflective to blue and ultraviolet light. The combined beam is passed through a field lens 114, the projection gate 104, the film image frame (including the informational portion 68 and the registration stripe 66), and through the projection lens 16 to the image plane 90 at the exposure station 18'. The flash lamp 14, preferably of the xenon type, is -mounted in an ellipsoidal reflector 110 which generally focuses the light beam toward a point beyond the projection gate 104 after being reflected first from a 45 planar mirror 112 and then from the 45 dichroic mirror 108. The infrared from the tungsten lamp 106 is incident on a 45 planar mirror 116 so as to reflect the radiation through a condenser lens 118, and through the dichroic mirror 108. All of the mirrors are disposed at 45 to the central rays incident thereto.

The strobe 14 emits an extremely intense light flash of actinic radiation for an extremely short duration, such as for a period less than 100 microseconds, to expose the film image onto the moving paper 12, which is only sensitive to the blue and ultraviolet spectrum.

With this optical and light source arrangement, continuous registration operation is permitted without fogging or discharging'the electrostatic charge which has been placed on the zinc-oxide-coated paper. Ultraviolet or blue spectral components in the radiation emission of the registration lamp 106 are reflected out of the optical path by the dichroic mirror 108 so that they cannot affect the electrophotographic paper. Likewise, any red or infrared component in the beam of the strobe 14 is transmitted through the dichroic mirror 108 and thus passes harmlessly out of the projection optical path.

Referring now back to FIG. 1 the paper transport system 20 comprises those units which directly control the mechanical movement and positioning of the paper web 12 throughout its passage along the paper path of the apparatus, and through the various stations of the electrostatic processing system, from the paper-loading cart 118, through an optional cleaning station 122, a charging station 124, a developer station 126, squeegee rollers 128, a drying station 130, a refold station 132 and then into the receiving cart 134. The supply cart 118 is wheeled on its track below the apparatus and the leading edge of the paper is fed up and into the apparatus, as shown schematically in FIG. 1, through suitable means for holding the paper web taut (not shown). I

The paper goes through the cleaning station 122 and enters the corona charging station 124 after being driven by the lower pinwheel assembly 31 which has apair of pinwheels along each respective marginal portion of the paper 12, engaging'the marginal sprocket holes therein, as previously mentioned. The charging station 124 may comprise any known form of corona charging structure to produce a suitable corona for charging the paper 12 to the proper polarity and potential for imaging.

After the corona charge has been placed on the paper 12, the web 12 is transported from the charging station 124, over roller guide disks 136, into the exposure station 18. The exposure station 18 is formed by a smooth steel plate or platen 138 perforated with airholes through which a partial vacuum is drawn, and which holds the paper web evenly (i.e., without flapping), and substantially wrinkle free over the platen surface, but permits its continuous movement thereover. Although the image plane 90 on the paper, the exposure station platen 138, and the masks 98 and 100 are shown spaced apart for the purpose of clarity of illustration, these parts are desirably closely spaced so that the paper is disposed on the platen 138 and the masks 98 and 100 are adjacent the surface of the paper. The platen 138 is mounted so that its flat surface slants upwardly at an angle which is perpendicular to the centerline of the optical path of the projection lens 16. The width of the exposure area on the paper is substantially the same width as the charged area thereon. The length of the exposure area in the direction of paper travel corresponds to each form section of the paper and is determined by adjustment of the upper and lower masks 98 and 100 forming the exposure window, as illustrated in FIG. 5. The masks 98 and 100 are positioned by sliding them up or down on support rods 140 and 142. The fold creases or tear perforations 96, 96, etc., defining the form sections of the paper 12, are desirably spaced about one-eighth inch from each respective exposure mask, and the charged area is preferably confined to the region between left and right marginal strips of approximately onehalf inch in width having the sprocket holes 27a and 27b centered therein.

Each time the strobe 14 is flashed, the image on the film strip is exposed on the charge-sensitized paper form registered within the exposure window and the paper is held evenly against the platen 138 with the tear perforations 96, 96', etc., spaced evenly from the respective upper and lower exposure masks 98 and 100. Photon bombardment discharges the paper in the exposed areas, forming a latent electrostatic image. As previously stated, the paper 12 is not stopped in the exposure station 18 during normal printing operation, but moves continuously therethrough.

After exposure, the paper 12 travels upwardly along the paper path, around first upper pinwheel assembly 30, and into the developer station 126. This is shown in FIG. 7 wherein arrows 152 and 154 show the direction of paper travel over the pinwheel assembly 30, which comprises marginally located pinwheels 156 and 158 for engaging the sprocket holes and a plurality of guide disks 160 mounted on a common shaft 162 with the pinwheels and disposed therebetween.

The developer station 126 may be of any known construction and generally comprises a developer tray, liquid solution tanks and suitable pumps that provide liquids to the developer tray and maintain appropriate volume levels for operation. After being developed, the paper 12 is fed between a pair of squeegee rollers 128 which press the excess solution from the paper web and also serve to maintain the web taut as it passes through the developer station, but of course not so taut as to cause tearing of the perforated sheets. The proper tension on the paper is maintained in the developer station by the squeegee rollers 128, the lower one of which is driven in synchronism with the entire paper transport drive system 20, through a pulley and slip clutch assembly mounted on the end of this roller and coupled to the pinwheel shaft 162 by a drivebelt, indicated by the dotted line 163. All of the mechanical couplings and drives of the paper transport system 20 are indicated by dotted lines, and these parts will be discussed in greater detail hereinafter.

The paper web 12 is then fed from the squeegee rollers 128 to the dryer station 130. The dryer station may comprise a dryer drum 164 over which the paper web passes, and an electric heater (not shown) placed in a stream of air directed onto the surface of the paper web as it passes over the dryer drurn 164. In this manner, each image is fixed onto'the paper to result in permanent hard copy that can be readily handled without loss of information.

After the paper web 12 passes over and around the dryer drum 164 and emerges from the drying station 130, it passes over the second upper pinwheel assembly 29 of the paper transport 20, and is then directed downwardly through the paper refold assembly 132 which refolds the paper and stacks it in the receiving cart 134 located at the lower part of the apparatus under the receiving station 46. The paper enters the refold assembly immediately after leaving the upper pinwheel assembly 29 which, as shown in greater detail in FIG. 7, comprises marginally located pinwheels 166 and 168, and guide disks 170 mounted on a common shaft 172 and located therebetween. The direction of paper travel over the upper pinwheel assembly 29 is shown by the arrow 174.

A pair of paper drive wheels 176 are located near the lower portion of the refold station 132 which are adapted to be opened initially to permit the feeding of the paper therebetween and then to be subsequently closed to maintain driving tension on thepaper web 12. A lever mechanism may be provided to manually open and close the guide wheels which are mechanically coupled to the paper transport mechanism, as shown by the dotted line 178 interconnecting the left drive wheel to the lower pinwheel assembly 31.

When each fan-fold crease passes over the lower end of the refold assembly 132, past the paper drive wheels 176, the weight of the paper sheet, itself, causes it to bend at each fold, and in this manner the paper refolds at its original creases as it is stacked in the receiving cart 134.

Turning now more specifically to the construction of the paper transport system 20, the upper paper transport assemblies 29 and 30 may preferably comprise two sets of approximately 7-inch-diameter pinwheels, one set above the other, and the pins on each set of pinwheels are kept in alignment with each other and with the marginal sprocket holes in the paper by suitable alignment rods inserted through holes in the pinwheels and through each set of paper support disks and 170. The lower pinwheelassembly 31 has a similar structure, but with a pair of approximately ZEQ-inch-diameter pinwheels and disks. A single paper transport drive motor 180 may be employed to drive the entire paper transport system 20, and in a specific construction of the illustrated apparatus, the paper transport drive motor 180 is coupled directly to the upper pinwheel assembly 30, as indicated by dotted line 181,

and to the lower pinwheel assembly 31 (dotted line 183) with a common drivebelt. The upper pinwheel assembly 30 then drives the other upper pinwheel assembly 29 by a set of suitable transfer gears (dotted line 185) coupled to their respective shafts 162 and 172. The squeegee rollers 128 and the paper drive wheels 176 are driven by suitable belt and pulley takeoffs as indicated by the dotted lines 163 and 178.

In accordance with the present'invention, proper paper registration and synchronization of the strobe lamp 14 to accommodate particular form formats of various lengthsis accomplished by providing suitable form registration programs as an input to the paper registration control 28, as generally described above. The form length in the direction of travel may typically vary from 8% inches to inches between successive folds or tear perforations 96, 96, etc. As can be seen, proper registration and flash synchronization for any one particular form length will be improper for another form length.

' Also, multiple forms may be provided between the successive folds or perforations.

The paper registration control 28 may comprise coarse and fine registration controls 50 and 54, illustrated in FIG. 2, which provide coarse and fine timing signalpulses on respective leads 52 and 56. The coarse registration control 50 preferably comprises, in accordance with the present embodiment of the invention, a program tape reader 204 employing a program loop or belt of'perforated tape 206, as shown in FIG. 7. As shown in greater detail in FIG. 10, the perforated tape 206 has a series of closely spaced sprocket holes 208 disposed longitudinally along the tape and a sequence of longitudinally spaced program holes 210, 210', etc., laterally offset therefrom and located between the sprocket holes 208 and one edge of the tape. The perforated program tape 206 is preferably formed from any normally opaque material, and may be composed of paper, plastic etc. A different program tape is used for each different form length and has a different fixed spacing between successive program holes 210, 210,

tional to the length of the forms. Thus, a relatively'long program hole spacing is used for long form lengths and a shorter.

program hole spacing is used for relatively shorter form lengths.

The fine registration control 54 has a fine registration adjustment means 212 with an adjustment knob 214, shown in FIG. 7, for manually setting the fine adjustment control 54 and obtaining precise synchronization of the flash strobe 14 with the registration of the form in the exposure station.

Referring now to FIG. 8, the program tape reader 204, fine adjustment means 212, and associated mechanisms are shown in greater detail. The shaft 162, on which are mounted the pinwheels 156 and 158 (FIG. 7), necessarily moves in accurate synchronism with the motion of the paper web 12 and provides the transport position input of the tape reader 204 that is related to the web motion and position, shown as input 32 in FIG. 2. The shaft 162 is geared to a transparent plastic sprocket wheel 216 whichdrives the program loop 206 by engagement with the sprocket holes 208 located therein. A gear 218is mounted on the end of the shaft162 and drives the plastic sprocket wheel 216 through gear 220. Thus, the program loop 206 is driven is synchronism with the movement of the paper web 12. A lamp 222 is mounted inside the transparent sprocket 216 and directs light onto tape reader photosensor 224 as each program hole passes therebetween to provide a timing pulse output each time a form on the web 12 is approximately centered in the exposure window on the platen 138. The photosensor 224 provides, in this manner, relatively long duration pulses as the coarse timing signal on lead 52 for synchronizing the flash of the strobe 14 with registration of the paper 12 for each exposure. These coarse timing pulses are fed to one input of the combining circuit 58, via lead 52.

The fine adjustment means 212 comprises, in the illustrated embodiment, a fine timing shutter wheel 226 (of which only a portion is shown in FIG. 8 for the purpose of better illustration) which is also driven by the same pinwheel shaft 162 via a friction slip clutch assembly 228, shown in FIG. 9. The timing wheel 226 has a multitude of alternate vanes 230 and notches 232 about its perimeter. A fine timing lamp 234 (FIG. 9) and a fine timing photosensor 236 are spaced on opposite sides of the timing wheel 226 and supported by means of a mounting bracket 238.

As the pinwheels rotate, moving the paper 12 through the apparatus, the timing wheel 226 rotates so that the vanes 230 intermittently block the light path between the timing lamp 234 and the timing photosensor 236 to generate a sequence or train of veryshort pulses from the latter. The frequency of these pulses is an integral multiple of the frequency of the coarse timing pulses in the present embodiment of the inven-' tion. The number of such short pulses is relatively large during any one form'length of paper travel, and these pulses are employed to achieve the fine registration adjustment of the web by permitting precise synchronization control of strobe flash with'the web position. These fine registration pulses are fed to the second input of the combining circuit 58 via lead 56.

The action of the coarse and fine registration pulses on leads 52 and 56 produces a vernier control whereby only the occurrence of both a coarse and a fine timing pulse produces an output pulse from the combining or coincidence circuit 58 for causing the strobe 14 to flash, and this output pulse on lead 34 is generated only on the occurrence of the first fine timing pulse after the leading edge of each coarse timing pulse. Thus, by adjusting the phase of the fine timing pulses relative to the portion of the web on which the image exposure is desired, the strobe 14 may be flashed at the precise instant that the desired portion is registered in the exposure station. I I

In order to provide this fine adjustment of paper registra tion, the timing lamp 234 and photosensor 236, mounted on bracket 238, are fixed to a rack 242 having a linear gearing portion 244 disposed along its lower surface and directed downward so as to engage a pinion gear 246, as shown'in FIG. 8. The pinion gear 246 is mechanically coupled to the fine registration adjustment knob 214 shown in FIG. 7, and by'turning this adjustment knob, the rack 242 and the timing photosensor 236 are moved to the left or right in a plane parallel to the timing wheel 226, thus retarding or advancing the fine timing pulses 202, as desired.

In order to set a definite relationship between the fine timing adjustment and the actual form registration, an initial adjustment may be made by moving the paper web 12 forward or backward at a slow speed until a form is centered or registered on the platen 138. While the paper form is centered but not moving, the sprocket 216 driving the perforated tape loop 206 is manually rotated until one of the program holes 210 in the tape is aligned with the program tape reader photosensor 224.

This manual rotation may be made by turning a reset knob 252 (FIG. 7) which is coupled to a gear 254 (FIG. 8) which, through suitable gearing arrangements, rotates the plastic sprocket drum 216 until a program hole is aligned with the light source 222 and the photosensor 224. The gear 218 slips with respect to the shaft 162 during this alignment, which is indicated by a suitable control panel indicator light (not shown) for indicating the program tape reader registration. A suitable slip clutch may be provided to permit this adjustment.

With the paper 12, loop 206, and timing wheel 226 stopped in this position, the fine timing adjustment knob 214 (FIG. 7) and thus pinion gear 246 (FIG. 8) are turned fully counterclockwise (as viewed in FIG. 8), driving the rack 242 to the extreme left until it strikes a stop 256 which is fixed to the frame of the apparatus. During this motion, a pawl 258 near the right end of the rack 242 strikes one of the shutter vanes or represented as pulse train 502a in FIG. 3f. The relative timing teeth 230 of the timing wheel 226'a'nd rotates the wheel 226.

'slips as the timing wheel 226 rotates on the shaft 162. The fine adjustment knob 214 (FIG. 7) and consequently'the pinion gear 246 are then rotated back to a position where the index mark on the panel is opposite a mark on the knob 214, as shown in FIG. 7. With the knob index at O, the lamp and photosensor assembly on the rack is positioned on a vertical Iineor axis which extends through the pinwheel shaft 162.

In operation, when the paper transport motor 180 is turned on, the pinwheels will move the paper 12 continuously through the exposure station 18, the coarse timing pulses will be generated as the program loop 206 passes the tape reader photosensor 224, and the fine timing pulses will be generated as the shutter vanes on the timing wheel 226 pass the photosensor 236. Referring to FIG. 3, the sequence of operations of the system, in accordance with the present embodiment of the invention, is illustrated graphically as a function of time. The scale in FIG. 30 represents the paper web 12 passing the center line 94 (FIG. of the exposure station 18, where the F-marks indicate the folds or perforations between the predetermined form portions and the C-marks indicate the centerlines or axes of the predetermined form portions. The passing of the web sprocket holes is represented by the dots in FIG. 3b, and eachv form portion is an integral number of sprocket holes in length. The relative position or timing of the form-folds F and the sprocket holes is fixed for any given web, and thus the relative timing of the form centerlines C and the sprocket holes does not vary for a given web, although it may be different on another web. The sprocket holes may thus serve as indexes or indications of the positions of the forms on a web. The program holes 210, 210', etc., in the tape loop 206 are represented in FIG. 36, and the photosensor signals derived from them are represented by the coarse timing pulses 500 in FIG. 3 d. The loop program holes 210 are spaced apart a distance equivalent to an integral number of web sprocket holes, and a particular program hole spacing on a tape loop is used for a particular form-fold spacing or form length on a web so that the periods or repetitive spacings of each will correspond when both are driven by the paper transport and tape reader mechanisms. Thus, although the coarse timing pulses 500 are always synchronous and in phase with the program holes 210, and both have the same period (or frequency) as the form centerlines C, their phase can be grossly different than that of the form centerlines C, as indicated by the dotted pulses 500a in FIG. 3d corresponding to the out of phase dotted program holes 210a in FIG. 30. However, the phase of both the program holes and the coarse timing pulses may be varied continuously or smoothly with respect to the paper centerlines C during the previously described initial adjustment of the printer, using knob 252 (FIG. 7), so that desirably the coarse timing pulses are approximately centered with the form centerlines C, and the duration or width and phase of each coarse timing pulse are such that each pulse is present before, during, and after the form centerline C passes the exposure station centerline 94 (FIG. 5). Once the printing operation has commenced, further adjustment of the relative timing of the coarse timing pulses 500 is not necessary since the instant of flashing is determined by the occurrence of a fine timing pulse in particular relationship to the coarse timing pulse in a manner to now be described.

When properly adjusted, the program holes serve as approximate indexes or indicators of form position relative to the exposure station. The program holes and coarse pulses are provided only to determine which of the many closely spaced fine pulses will trigger the flash; i.e., how frequently the flash will be triggered.

The fine timing pulses from the fine registration control 54, when properly adjusted, are represented by the pulse train 502 in FIG. 3e and the same signals, but improperly adjusted, are

or phase of the fine timing pulse train 502 with respect to the form centerlines C (FIG. 32) is adjusted by the knob 214 (FIG. 7) connected to the'rack 242 and pinion 246' (FIG. 8) during the operation of the apparatus, the initial adjustment for referencing being made by the slipping of clutch 228 in the manner previously described.

Considering the coarse and fine timing pulses of FIG. 3d and FIG. 3e, respectively, on respective leads 52 and 56 (FIG. 2), these timing pulses are fed to the combining circuit 58. More specifically, the coarse timing pulses are fed to the input of a differentiator 504 to provide a sequence or train of spikes 506 (FIG. 3i), each generally coincident with the leading edge of each coarse timing pulse 500. The fine timing pulses 502 are likewise fed through a differentiator 508 to provide the sequence of spikes 510 (FIG. 3g), each coincident with the leading edge of these timing pulses. The coarse timing spikes 506 function to set a flip-flop or bistable multivibrator 512, comprised of two cross-coupled NAND gates, via inverter 514 coupled to the set input thereof. The first fine timing spike 510 occurring after the flip-flop 512 is set, resets the flip-flop via inverter 516 coupled to the reset input thereof. Consequently, the output of the flip-flop 512 on lead 518 appears as a pulse 520 (FIG. 3j) having its leading edge coincident with the occurrence of a coarse timing spike 506 and its trailing edge coincident with the first fine timing spike 510 occurring thereafter. The negative-going trailing edge of each of the output pulses 520'from the flip-flop 512 is difierentiated by a series connected capacitor 522 and a parallel connected resistor 524 connected to a positive voltage supply, as shown. The resulting negative spikes are inverted by an inverter circuit 526 to provide positive pulses (FIG. 3k) coincident with the trailing edge of each flip-flop output pulse 520. The positive pulses or spikes 528 are then applied to one input of a NAN D gate 530. The other input to the NAND gate 530 is supplied by a STROBE ENABLE signal derived from either a suitable connection to a control panel sw'tch (not shown) or to suitable circuitry responsive to the registration photocell detector 26 (FIGS. 1 and 5),as will be later explained. If the STROBE ENABLE signal is present on the second input to NAND gate 530 when the pulse 528 occurs, the STROBE output 34 drops to a relatively low value as indicated by negative-going pulses 532 (FIG. 3n) coincident with the occurrence of each of the spikes 528, and hence coincident with the first fine timing spike 510 occurring subsequent to a coarse timing spike 506. The negative-going pulses or spikes 532 each cause the strobe 14 to be triggered at the precise instant when the centerline C of each form portion is centered in the exposure station 18.

In some applications it may be desired that the control logic 36 (FIG. I) normally inhibit the actuation of the strobe 14 unless it is enabled by a signal from the registration photosensor 26, indicating that a projected image is registered in the exposure station and is therefore ready for exposure. Thus, with the enabling registration signal, illustrated in FIG. 3m as pulses 534, fed to the second input of the NAND gate 530 (FIG. 2), the strobe-flashing pulses 532 provide a trigger signal on lead 102 (FIG. 1) which actuates or flashes the strobe lamp 14. During single copy operation, the registration pulses 534 may extend from some time prior to each strobe-flashing pulse 532 and terminate shortly thereafter as the microfilm 10 is moved to the next successive image frame. But when the multiple copy circuit 38 is set for more than one copy of each image, the registration pulses 534 will not terminate until shortly after the last of a number of strobe-flashing pulses 532 have occurred, such number corresponding to the preselected number of copies of each image to be made.

As can be seen, then, the relationship between the fine timing pulses and any given portion of the web, such as the centerline of each form portion thereof, may be adjusted while the paper is moving through the apparatus at high speed in normal operation and any desired registration may be obtained by observation of the microfilm information as it is printed out on the forms in the output, the fine adjustment knob 214 being rotated slightly until the desired results are obtained. For example, if the fine adjustment knob 214 were rotated to advance the fine timing pulse train to the phase shown in FIG. 3f, producing the fine timing spikes shown in FIG. 3h, the strobe 14 would be triggered somewhat earlier than shown in FIG. 3n, and each flash would occur prior to the form centerlines reaching the centerline of the exposure station 18. This extremely fine adjustability permits an operator to obtain the precise registration which is necessary to print variable information from the microfilm onto forms which are preprinted, where any misregistration would be extremely noticeable and intolerable. And additionally, this adjustment may be made without requiring any slowdown or stoppage of the web.

The differentiating circuits 504 and 508 may be of any known suitable type; but in accordance with one construction of the present embodiment of the invention, they comprise a unijunction transistor having its emitter coupled to a capacitor which is charged to a given potential, and the timing pulse inputs are coupled across the base electrodes so that when the input base becomes sufficiently positive to equal the voltage established at the emitter, the capacitor is rapidly discharged through a load resistor in the output base, generating the positive going spikes illustrated in FIGS. 3g, 3h and 3i. However, other forms of circuitry to produce equivalent results may alternatively be employed.

Thus, the sequence of operations of the apparatus may be summarized in that first the film is advanced rapidly until the center or axis of a film frame is near the projection aperture center (and the center of its projected image is near the center of the exposure station), then it is advanced slowly until exactly at center, and then the film is stopped. A flash enabling registration signal may be supplied to the control logic, as previously described. The paper forms move continuously and at constant speed at all times. After the film is stopped, the axis of a form reaches a position near the axis of the exposure platen and a relatively long duration coarse timing pulse is generated. When the axis of the paper form reaches the exact center of the exposure platen, a fine timing pulse is generated incoincidence with the coarse pulse, which causes the strobe lamp to flash at this time.

The tape reader 204 is desirably constructed with a springloaded housing 260 having tape slots 261 for receiving the tape loop 206, and the housing may be manually depressed downward for inserting or removing the program tape 206. The normally upward urging of the spring loading, causes the housing 260 to retain the tape 206 in engagement with the sprocket wheel 216 at the lower portion thereof. The portion 262 of the housing is recessed away from the upper portion of the sprocket wheel 216 to provide adequate clearance for the downward movement of the housing for releasing the tape from the lower portion of the sprocket wheel and for inserting a different tape thereon. The rack 242 may be supported by any suitable means, such as a sliding cam and slot support mechanism, and the pawl 258 may be pivotably mounted on the rack and urged upwardly by a spring 264 so that it will be deflected without damage in the event of accidental contact with the timing wheel 226 while the wheel is in motion. Other arrangements and forms of construction may of course be employed; for example, the positions of the pawl 258 and the stop 256 may be reversed. Also, for example, other arrangements of the timing wheel 226 with respect to the reader assembly 204 may be used, as well as with other forms of gearing or other mechanical coupling.

Additionally, although the use of a vaned timing wheel, driven by the paper transport, and a photosensor provides a reliable source of pulses which are necessarily and continuously synchronized with the web movement, other and various forms of pulse generation may be employed in accordance with the principles of the invention in its broader aspects. However, the use of the vaned shutter wheel driven by the v pinwheel transport in the present embodiment, in accordance with somewhat narrower aspects of the invention, has certain advantages over certain other systems which might be employed, such as, for example, one using the web sprocket holes directly for the fine timing pulse generation. The paper web 12 which as been slit to width from larger rolls, and then perforated and folded, usually carries with it some loose particles, such as dust, slivers, chads from the perforations, flakes of coating, etc., and thus the use of the shutter wheel and its associated light and photosensor, being well removed from the paper, avoids interference by these particles with the generation of the fine timing pulses. Also, the vacuum cleaning station 122, shown in FIG. 1, may be eliminated, if desired, and satisfactory operation will still be achieved.

Referring now to FIGS. 11 and 12, there is shown a portion of the logic circuitry which may be employed in the strobe and film transport control logic 36 and the multiple copy set and counter 38, illustrated in block form in FIG. 1. However, it is of course understood that other alternativeforms of logic and control circuitry may be used, such circuitry being within the skill of the art based on the teachings hereof. Generally, referring first to FIG. 1, the multiple copy circuit 38 comprises a multiple position selector switch by which the desired number of copies of each data frame is preselected, a counting circuit of any suitable type which is responsive to each flash of the strobe 14 to register the printing of each copy, and a comparator circuit which compares the preselected count on the selector switch with the count of the counter circuit to provide an output on lead 280 to the control logic 36 when the counter has reached the preselected count. This signal indicates that the preselected number of copies of the projected image have been exposed, and the control logic 36 then causes the film transport 24 to move themicrofilrn 10 to the next successive image frame, in the manner previously described. Also, a reset signal is supplied to the counter circuit via lead 282 to restore the counter to zero in preparation for the printing of the next image frame.

More particularly, referring now to FIG. 11, the copy selector switch 300 has a four-digit parallel binary output on leads 302, 303, 304 and 305 formed by four single-pole switches which are selectively opened and closed in the appropriate combinations to provide binary outputs corresponding to the selected number of copies to be made, as set on a suitable selection knob. (not shown), coupled to the switches. The switches may thus be suitably ganged. The selector switch 300 is illustrated in position'9" for preselection of nine copies of each projected film image, and the binary parallel outputs thus form the binary number 1001. These outputs are then inverted by inverter circuits 308, 309, 310 and 311 which transform the direct parallel switch outputs to 01 10 which is supplied on leads 314, 315, 316 and 317 to a comparison gating circuit 320. The comparison gating circuit 320 receives inputs from both the direct and inverted outputs of the selector switch 300, as well as the output count from a counting circuit 322 to provide a parallel comparison identity indication I for each respective binary digit on output leads 324, 325, 326 and 327. These leads are fed to an, output NAND gate 330 which provides a number correspondence output at 332 which is indicative of the exact correspondence between the counter output and the preselected switch number.

A counter stepping circuit 334 is provided which is responsive to a strobe monitoring signal on its input lead 336 each time the strobe 14 is flashed. The stepping circuit input lead 336 may be coupled to any suitable circuit point for monitoring the strobe flash and may conveniently be connected to a point in the strobe power supply (not shown). Other stepping circuit input leads 338, 340 and 342 are provided to supply inhibit signals from various other portions of the logic system (not shown) so that the stepping circuit 334 and the counter 322 may be inhibited for other modes of apparatus operation, such as, for testing or initially setting up the apparatus.

The output of the stepping circuit 334 appears at lead 344, and is coupled to the input of the counter 322 through a coupling resistor, as shown. The counter 322 comprises four J K flip-flops having their respective principal outputs (0) connected to tl 1eir K inputs, and their respective complementary outputs (Q) connected to their .I inputs. The stepping circuit output on lead 344 is coupled to the'trigger input (T) of theselector switch 300. Each of these comparison gating stages comprises three two-input NAND logic gates 350a, 350k and 3500; 3510, 351b and 3510, etc., being connected so that the output terminals of the a and b gates are connected respectively to the two inputs of the c gates, and the output of each gate is connected to its respective output lead 324, 325, 326 and 327. These leads provide four inputs to the output NAND logic gate 330, corresponding to the correspondence indication of each binary digit.

These circuits are interconnected so that each of the direct outputs from the selector switch 300 on leads 302, 303, 304 and 305 are respectively connected to one of the b gate inputs, while the inverted selector switch outputs on leads 314, 315, 316 and 317 are each connected to one of the respective a gate inputs. The complementary output of each .I-K flip-flop stage of the counter 322 is respectively connected to the other a gate input of each corresponding stage of the comparison gating circuit 320, while the principal output of each of these flip-flops is connected to the other input of each b gate of the corresponding comparison gating circuit stage.

Thus, when the binary output count of the counter 322 has reached the preselected number count set on the selection switch 300, the output of the c gates in each of the comparison gating stages will be in the 1 state and the output of NAND gate 330 at lead 332 will be in its 0 state.

Referring now to FIG. 12, the number correspondence signal on lead 332, which indicates that the preselected number of exposures of an image frame have been completed, is fed to the toggle or T-input of rnulticopy-end flip-flop circuit 370 through a NAND gate 372 and an inverter 374. The flipflop 370 is in the cleared or zero state while the counter 322 is counting flashes so it is switched to the one state by the number correspondence signal. When the rnuIticopy-end flipflop 370 is thus triggered, the output on lead 376 enables gate 378. When the other input of gate 378 is subsequently enabled by the output of gate 418, as will be described later, it provides a reset signal on lead 346 by means of NAND gate 380 and inverter 382, the reset signal on lead 346 being fed to the counter 322 (FIG. 11) which is restored to 0. The reset signal on lead 346 is also applied via lead 428 to the reset input of the multicopy-end flip-flop 370 to restore its initial state at the same time that the counter circuit 322 is restored to 0. The principal output on lead 376 also provides an INCREMENT signal at terminal 384 by means of NAND gate 386 and a EARCH signal at terminal 388 by means of NAND gate 390, when the otherappropriate signal inputs are applied to these gates, as will hereinafter be described.

The I'NCREMENT signal at terminal 384 is supplied to a capstan drive circuit (not shown) which causes the capstan on film transport 24 (FIG. 1) to move the film toward the next successive image frame. When the change-speed photosensor 92 intercepts the light from the projected film registration mark, this photosensor provides a pulse to the terminal 392 which sets stop-enable flip-flop circuit 394, comprising two cross-connected NAND gates, as shown. The flip-flop 394 is set through NAND gates 396, 398, 400 and inverter 402, and provides a principal output on lead 404 which is coupled to a second input of the NAND gate 390. The presence of these signals in suitable form at the inputs of the.NAND gate 390 causes this logic gate to provide the output signal to the capstan drive circuit, causing the film capstan to move the film at a slow speed for image registration in the manner previously described.

Subsequently, then, the registration photosensor 26 intercepts the light from the projected film registration mark and provides a pulse 534 (FIG. 3m) at terminal 408, which isamplified by a transistor amplifier circuit 410. The amplified pulse triggers stop flip-flop 412 (also comprised of two crossconnected NAND gates) through NAND gates 414, 416 and 418. The complementary output of the stop flip-flop 412 is a FAST STOP signal on terminal 420 which is applied to the capstan drive circuit, which immediately brings the film to a stop for proper registration in the exposure station 18. The signal from nand gate 418, which triggers the stop flip-flop 412 also is applied to NAND gate 378. Since the other input to NAND gate 378 is already present, a reset signal is generated on lead 346, as described before, coincident with the FAST shown) is coupled, as shown, to the flip-flop 370 via gate 372 v and to the flip-flops 394 and 412, and serves to reset these flipflops in the normal mode of system operation. A CLEAR signal at terminal 430 may be supplied from a suitable control panel switch for manually resetting the counter 322 and the multicopy-end flip-flop 370. Leads 432, 433 and 434 are provided for auxiliary circuitry which may be employed for operating the system in a setup or test mode where it may be desirable to inhibit the photosensor operations and to supply simulated pulses generated by other circuits included in the apparatus for this purpose, and not shown herein.

Thus, a high-speed printing apparatus has been illustrated and described for printing microfilm images onto a hard copy medium, such apparatus having the capacity of producing throughputs of at least feet per minute in a continuous manner on blank or preprinted paper. The paper may be preprinted with, for example, letterheads, invoice forms or other fixed information, and the variable information from the microfilm is then added to the preprinted forms with exact registration by flashing a high-intensity strobe in synchronism with the registration of the continuously moving forms in the exposure station of the apparatus. The synchronization and registration relationships for different size forms or formats may be conveniently changed as desired by using appropriate program tapes, and precision adjustmentis accomplished by a photoelectromechanical vernier action.

Although the present invention has been described in connection with a flash synchronization and paper registration system for a high-speed printer using fan-folded, sprocket-perforated paper, the principles thereof may be employed in printing apparatus using paper in other forms, such as paper rolls. The paper web preferably comprises some means, such as marginal sprocket holes, for assuring that the paper movement is synchronized with the paper transport mechanisms. In some applications, a single projected frame of the microfilm may be sufficient to fill in a number of forms or other predetermined portions of the paper. Furthermore, two, three or four forms may be placed in the interval between successive fold lines 96, 96' etc. Also, forms of relatively narrower width may be placed side by side across the width of a relatively wide web of paper, so that two or more forms may be placed side by side across the web, between sprocket holes 27a and 27b.

In accordance with the broader aspects of the present in vention, the principles thereof may be applied to methods and apparatus for synchronizing a functional operation, generally, to predetermined portions of a high-speed moving web, wherein the predetermined portions of the web are placed in registration to receive the functional operations thereon.

Although a preferred embodiment in accordance with the present invention has been illustrated and described, various modifications will be apparent to those skilled in the art; and accordingly, the scope of the present invention should be defined only by the claims, and equivalents thereof.

Various features of the invention are set forth in the following claims.

What is claimed is:

l. A system for synchronizing the action of a functional operation on a continuously moving web with respect to predetermined portions thereof moving through a station wherein the operation is to be performed, said system comprising first means responsive to the movement of said web for providing a first output in the form of a first train of electrical pulses having a frequency corresponding to the frequency with which said portions pass said station, and indicative of said predetermined web portions being approximately registered in said station, second means for providing a second output in the form of a second train of electrical pulses of higher frequency than said first mentioned pulse train, third means responsive to said first pulse train and said second pulse train for providing an output for actuating said operation on the occurrence of both a pulse of said first pulse train and a pulse of said second pulse train in a predetermined relation to each other, and means for adjustably varying the timing of said second pulse train with respect to the times at which said portions of the web pass said stations so that the occurrence of the output may be synchronized with the instant that a predetermined web portion is in precise registration therein.

2. The system of claim 1 comprising means for adjusting the timing of said first pulse train relative to the times at which said web portions pass said station so that each pulse of said first train commences prior to the time that said predetermined web portion is precisely registered therein, and said third means comprises means for producing said output only on the occurrence of. the first pulse in said second pulse train occurring after each pulse of said first pulse train commences.

3. The system of claim 1 wherein said means for providing said first output comprises a tape reader for reading indexes from a program tape indicative of the approximate registration of each predetermined web portion in said station, said reader comprising means for moving said tape in synchronism with the web and means for detecting the indexes of the tape, said indexes being discrete and spaced apart a distance proportional to the distance between the centers of successive predetermined portions of the web.

4. The system of claim 3 further comprising transport means for synchronously and continuously moving the web through said station, and wherein said tape readercomprises a sprocket wheel coupled to said transport means for engaging a row of closely spaced sprocket holes in the program tape, the tape being generally opaque and the detectable indexes thereof being formed by a further row of holes offset from the sprocket holes. I

5. The system of claim 1 wherein said second means comprises a light source, a photosensor, and a shutter wheel for intermittently blocking and passing the optical path between the light source and the photosensor so that said second train of pulses is provided from the output of said photosensor, means for turning said shutter wheel in synchronism with the web movement, and said means for adjustably varying the timing of said second pulse train comprises means for moving the photosensor so as to advance or retard the pulses.

6. The system of claim 5 wherein said means for providing said first output comprises a tape reader for reading indexes from a program tape indicative of the approximate registration of each predetermined web portion in said station, said system further comprising transport means for continuously moving the web through said station, and means coupled to said transport means for moving said tape in synchronism with said web.

7. The system of claim 1 comprising transport means for continuously moving the web through said stations, said transport means including pinwheel assemblies for drivably engaging sprocket holes in said web to assure synchronism between the transport means and the web.

8. The system of claim 1 for synchronizing the exposure of a photographic image on a continuously moving photosensitive web in registration with predetermined portions thereof at an exposure station, said system comprising a light source for exposing said image onto said web, and means coupling said third means to said light source for actuation thereof on the occurrence of said output signal.

9. The system of claim 8 wherein the photographic image is on a microfilm medium and said photosensitive web comprises electrophotographic paper, said system further comprising means for projecting an enlarged version of the image onto the moving paper and an electrostatic printing system for recording the enlarged image thereon.

10. The system of claim 8 wherein said photographic image may be moved into and out of registration with respect to the exposure station, said system comprising detecting means responsive to the registration of said photographic image in the exposure station for enabling the output from said third means only when said photographic image is registered in the exposure station.

11. The system of claim 1 wherein said second means comprises a light source, a photosensor, and a shutter wheel for intermittently blocking and passing the optical path between the light source and the photosensor so that said second train of pulses is provided from the output of said photosensor, means for turning said shutter wheel in synchronism with the'web movement, and said means for adjustably varying the timing of said second pulse train comprises means for moving the light source so as to advance or retard the pulses.

12. A method for synchronizing the action of a functional operation on a continuously moving web with respect to regular periodic predetermined portions thereof moving through a station wherein the operation is to be performed, comprising the steps of providing first indications at times when a predetermined web portion is approximately registered in said station, providing second indications synchronous with the movement of the web in the form of a train of pulses having a rate greater than that of said first indications, and comparing said first indications with said train of pulses to derive a third indication only as each predetermined web portion is approximately registered in said station and at a time determined by the phase of said train of pulses relative to the passing of said predetermined portions through a position of desired registration with said station.

13. In a system for synchronizing the projection of an image onto predetermined portions of a continuously moving photosensitive web, a transport means for synchronously and continuously moving the web through an exposure station at constant speed, a flash lamp for projecting said image onto said photosensitive web at the exposure station, means coupled to said transport means and thereby being responsive to the positions of said portions of the web with respect to the exposure station for providing an output indicative of each predetermined portion of the web being registered therein, said means coupled to said transport means includes program means for defining the spacing between the centers of successive projected images on the web, and means responsive to said outputs for actuating said flash lamp.

14. The system of claim 13 wherein said program means includes a tape reader coupled to said transport means for providing pulse outputs in response to spaced indexes on a program tape, the spacing between indexes being proportional to the spacing between the centers of successive predetermined portions of the photosensitive web.

'15. The system of claim 14 comprising means for providing a train of electrical pulses of such rate and duration so that a multitude of pulses are produced between successive reader output pulses, means responsive to said reader output pulses and said pulse train for providing said indicative output upon each receipt of a reader pulse and a pulse of the pulse train, and means for adjustably varying the phase of said pulse train with respect to the passage of said portions of the web through the exposure station so that the occurrence of said indicative outputs may be advanced or retarded at will to achieve the desired synchronization of flash lamp actuations with the instants of registration of predetermined portions of the web in said stationl 16. The system ofclaim 15 wherein said photosensitive web comprises successive form portions thereon defining said predetermined web portions.

17. The system of claim 16 wherein lateral lines of perforations spaced along the length of the web define web segments, and an integral number of said form portions are contained within each segment.

18; The system of claim 17 wherein said form portions are preprinted with fixeddata and adapted to receive the projected image in registration therewith.

19. A system for synchronizing the action of a functional operation on a continuously moving web with respect to regular periodic predetermined portions thereof passing through a station wherein the operation is to be performed, said system comprising means for providing a first sequence of pulses having the same period between pulses as the period of said predetermined web portions passing said station, means for adjusting the phase of said first sequence of pulses to be approximately the same as that of the passing of said periodic predetermined web portions through said station, means for each predetermined web portion is precisely registered therein.

20. The system of claim 19 wherein the pulses of said first sequence each begin at a time prior'to registration of the predetermined web portions in said station and terminate at a time thereafter. a

21. A' system for synchronizing the action of a functiona operation on a continuously moving web with respect to. a predetermined portion thereof moving through a station wherein the operation is to be performed, said system comprising first means responsive to the movement of said web for providing an electrical pulse indicative of said predetermined web portion being approximately registered in said station, second means for providing a train of electrical pulses having a frequency which is synchronized with the speed of the web through the station, third means responsive to said first-mew tioned pulse and said pulse train for providing an output for actuating said operation on the occurrence of both a pulse of said pulse train and said first-mentioned pulse in a predetermined relation to each other, and means for adjustably varying the phase of said pulse train with respect to the passage of said portion of the web through the station so that the occurrence of said output may be synchronized with the instant that said web portion is in precise registration therein.

22. A method for synchronizing the action of a functional operation on a continuously moving web with respect to regular periodic predetermined portions thereof moving through a station wherein the operation is to be performed, comprising the steps of providing first indications at times when a predetermined web portion is approximately registered in said station, providing second indications synchronous with the movement of the web in the form of a train of pulses having a rate greater than that of said first indications, comparing said first indications with said train of pulses to derive a third indi cation only as each predetermined web portion is approximately registered in said station and at a time determined by the phase of said train of pulses relative to the passing of said portions through said station, and adjusting the phase of said train of pulses so that it is in a predetermined relation with respect to the passing of the portions of the web-through said station so that said third indications occur when a predetermined portion of the web is in the desired registration with said station.

23. The method of claim 22 wherein the steps of providing first and second indications comprise, respectively, generating first electrical pulses having a first frequency and commencing prior to registration of each predetermined web portion in said station .and generating a train of electrical pulses having a second frequency, said second frequency being an integral multiple of said first frequency, and adjusting the phase of said pulse train so that there is coincidence between one pulse of the pulse train and registration of a predetermined web portion in said station after each of said first pulses.

24. The method of claim 23 wherein the first pulses are generated by detecting spaced indexes on a replaceable program tape moved in synchronism with the web, the spacing between indexes being proportional to the spacing between successive predetermined portions of the web.

25. A method for synchronizing the exposure of an image onto a continuously moving photosensitive web with respect to predetermined portions thereof, comprising the steps of continuously moving the web through an exposure station by means of a web transport, monitoring the movement of the transport with respect to a reference to derive an indication when a predetermined web portion is registered in said exposure station; said indication being derived by comparing a first electrical signal with a second electrical signal, the first signal being generated by detecting spaced indexes on a program tape moved in synchronism with said web to provide a pulse upon the approximate registration of each predetermined web portion in the exposure station, and the second signal being generated by producing a multitude of short duration pulses between the generation of each of said first-mentioned pulses, adjusting the phase of the first signal relative to the movement of said portions through said station so that the portions are in precise registration after the occurrence of said pulse, and ad- 

1. A system for synchronizing the action of a functional operation on a continuously moving web with respect to predetermined portions thereof moving through a station wherein the operation is to be performed, said system comprising first means responsive to the movement of said web for providing a first output in the form of a first train of electrical pulses having a frequency corresponding to the frequency with which said portions pass said station, and indicative of said predetermined web portions being approximately registered in said station, second means for providing a second output in the form of a second train of electrical pulses of higher frequency than said first mentioned pulse train, third means responsive to said first pulse train and said second pulse train for providing an output for actuating said operation on the occurrence of both a pulse of said first pulse train and a pulse of said second pulse train in a predetermined relation to each other, and means for adjustably varying the timing of said second pulse train with respect to the times at which said portions of the web pass said stations so that the occurrence of the output may be synchronized with the instant that a predetermined web portion is in precise registration therein.
 2. The system of claim 1 comprising means for adjusting the timing of said first pulse train relative to the times at which said web portions pass said station so that each pulse of said first train commences prior to the time that said predetermined web portion is precisely registered therein, and said third means compriseS means for producing said output only on the occurrence of the first pulse in said second pulse train occurring after each pulse of said first pulse train commences.
 3. The system of claim 1 wherein said means for providing said first output comprises a tape reader for reading indexes from a program tape indicative of the approximate registration of each predetermined web portion in said station, said reader comprising means for moving said tape in synchronism with the web and means for detecting the indexes of the tape, said indexes being discrete and spaced apart a distance proportional to the distance between the centers of successive predetermined portions of the web.
 4. The system of claim 3 further comprising transport means for synchronously and continuously moving the web through said station, and wherein said tape reader comprises a sprocket wheel coupled to said transport means for engaging a row of closely spaced sprocket holes in the program tape, the tape being generally opaque and the detectable indexes thereof being formed by a further row of holes offset from the sprocket holes.
 5. The system of claim 1 wherein said second means comprises a light source, a photosensor, and a shutter wheel for intermittently blocking and passing the optical path between the light source and the photosensor so that said second train of pulses is provided from the output of said photosensor, means for turning said shutter wheel in synchronism with the web movement, and said means for adjustably varying the timing of said second pulse train comprises means for moving the photosensor so as to advance or retard the pulses.
 6. The system of claim 5 wherein said means for providing said first output comprises a tape reader for reading indexes from a program tape indicative of the approximate registration of each predetermined web portion in said station, said system further comprising transport means for continuously moving the web through said station, and means coupled to said transport means for moving said tape in synchronism with said web.
 7. The system of claim 1 comprising transport means for continuously moving the web through said stations, said transport means including pinwheel assemblies for drivably engaging sprocket holes in said web to assure synchronism between the transport means and the web.
 8. The system of claim 1 for synchronizing the exposure of a photographic image on a continuously moving photosensitive web in registration with predetermined portions thereof at an exposure station, said system comprising a light source for exposing said image onto said web, and means coupling said third means to said light source for actuation thereof on the occurrence of said output signal.
 9. The system of claim 8 wherein the photographic image is on a microfilm medium and said photosensitive web comprises electrophotographic paper, said system further comprising means for projecting an enlarged version of the image onto the moving paper and an electrostatic printing system for recording the enlarged image thereon.
 10. The system of claim 8 wherein said photographic image may be moved into and out of registration with respect to the exposure station, said system comprising detecting means responsive to the registration of said photographic image in the exposure station for enabling the output from said third means only when said photographic image is registered in the exposure station.
 11. The system of claim 1 wherein said second means comprises a light source, a photosensor, and a shutter wheel for intermittently blocking and passing the optical path between the light source and the photosensor so that said second train of pulses is provided from the output of said photosensor, means for turning said shutter wheel in synchronism with the web movement, and said means for adjustably varying the timing of said second pulse train comprises means for moving the light source so as to advance or retard the pulses.
 12. A method for synchroniziNg the action of a functional operation on a continuously moving web with respect to regular periodic predetermined portions thereof moving through a station wherein the operation is to be performed, comprising the steps of providing first indications at times when a predetermined web portion is approximately registered in said station, providing second indications synchronous with the movement of the web in the form of a train of pulses having a rate greater than that of said first indications, and comparing said first indications with said train of pulses to derive a third indication only as each predetermined web portion is approximately registered in said station and at a time determined by the phase of said train of pulses relative to the passing of said predetermined portions through a position of desired registration with said station.
 13. In a system for synchronizing the projection of an image onto predetermined portions of a continuously moving photosensitive web, a transport means for synchronously and continuously moving the web through an exposure station at constant speed, a flash lamp for projecting said image onto said photosensitive web at the exposure station, means coupled to said transport means and thereby being responsive to the positions of said portions of the web with respect to the exposure station for providing an output indicative of each predetermined portion of the web being registered therein, said means coupled to said transport means includes program means for defining the spacing between the centers of successive projected images on the web, and means responsive to said outputs for actuating said flash lamp.
 14. The system of claim 13 wherein said program means includes a tape reader coupled to said transport means for providing pulse outputs in response to spaced indexes on a program tape, the spacing between indexes being proportional to the spacing between the centers of successive predetermined portions of the photosensitive web.
 15. The system of claim 14 comprising means for providing a train of electrical pulses of such rate and duration so that a multitude of pulses are produced between successive reader output pulses, means responsive to said reader output pulses and said pulse train for providing said indicative output upon each receipt of a reader pulse and a pulse of the pulse train, and means for adjustably varying the phase of said pulse train with respect to the passage of said portions of the web through the exposure station so that the occurrence of said indicative outputs may be advanced or retarded at will to achieve the desired synchronization of flash lamp actuations with the instants of registration of predetermined portions of the web in said station.
 16. The system of claim 15 wherein said photosensitive web comprises successive form portions thereon defining said predetermined web portions.
 17. The system of claim 16 wherein lateral lines of perforations spaced along the length of the web define web segments, and an integral number of said form portions are contained within each segment.
 18. The system of claim 17 wherein said form portions are preprinted with fixed data and adapted to receive the projected image in registration therewith.
 19. A system for synchronizing the action of a functional operation on a continuously moving web with respect to regular periodic predetermined portions thereof passing through a station wherein the operation is to be performed, said system comprising means for providing a first sequence of pulses having the same period between pulses as the period of said predetermined web portions passing said station, means for adjusting the phase of said first sequence of pulses to be approximately the same as that of the passing of said periodic predetermined web portions through said station, means for providing a second sequence of pulses having a substantially shorter period than said first sequence, means responsive to said first and second pulse sequences for providinG an output only on the occurrence of the first pulse in the second sequence occuring after the onset of each pulse of the first sequence, and means for varying the phase of said second pulse sequence with respect to the passing of the web portions through said station so that said output is obtained only when each predetermined web portion is precisely registered therein.
 20. The system of claim 19 wherein the pulses of said first sequence each begin at a time prior to registration of the predetermined web portions in said station and terminate at a time thereafter.
 21. A system for synchronizing the action of a functional operation on a continuously moving web with respect to a predetermined portion thereof moving through a station wherein the operation is to be performed, said system comprising first means responsive to the movement of said web for providing an electrical pulse indicative of said predetermined web portion being approximately registered in said station, second means for providing a train of electrical pulses having a frequency which is synchronized with the speed of the web through the station, third means responsive to said first-mentioned pulse and said pulse train for providing an output for actuating said operation on the occurrence of both a pulse of said pulse train and said first-mentioned pulse in a predetermined relation to each other, and means for adjustably varying the phase of said pulse train with respect to the passage of said portion of the web through the station so that the occurrence of said output may be synchronized with the instant that said web portion is in precise registration therein.
 22. A method for synchronizing the action of a functional operation on a continuously moving web with respect to regular periodic predetermined portions thereof moving through a station wherein the operation is to be performed, comprising the steps of providing first indications at times when a predetermined web portion is approximately registered in said station, providing second indications synchronous with the movement of the web in the form of a train of pulses having a rate greater than that of said first indications, comparing said first indications with said train of pulses to derive a third indication only as each predetermined web portion is approximately registered in said station and at a time determined by the phase of said train of pulses relative to the passing of said portions through said station, and adjusting the phase of said train of pulses so that it is in a predetermined relation with respect to the passing of the portions of the web through said station so that said third indications occur when a predetermined portion of the web is in the desired registration with said station.
 23. The method of claim 22 wherein the steps of providing first and second indications comprise, respectively, generating first electrical pulses having a first frequency and commencing prior to registration of each predetermined web portion in said station and generating a train of electrical pulses having a second frequency, said second frequency being an integral multiple of said first frequency, and adjusting the phase of said pulse train so that there is coincidence between one pulse of the pulse train and registration of a predetermined web portion in said station after each of said first pulses.
 24. The method of claim 23 wherein the first pulses are generated by detecting spaced indexes on a replaceable program tape moved in synchronism with the web, the spacing between indexes being proportional to the spacing between successive predetermined portions of the web.
 25. A method for synchronizing the exposure of an image onto a continuously moving photosensitive web with respect to predetermined portions thereof, comprising the steps of continuously moving the web through an exposure station by means of a web transport, monitoring the movement of the transport with respect to a reference to derive an indication when a predetermined web pOrtion is registered in said exposure station; said indication being derived by comparing a first electrical signal with a second electrical signal, the first signal being generated by detecting spaced indexes on a program tape moved in synchronism with said web to provide a pulse upon the approximate registration of each predetermined web portion in the exposure station, and the second signal being generated by producing a multitude of short duration pulses between the generation of each of said first-mentioned pulses, adjusting the phase of the first signal relative to the movement of said portions through said station so that the portions are in precise registration after the occurrence of said pulse, and adjusting the phase of the short pulses for a particular time relationship with the movement of the portions of the web so that the predetermined web portions are in precise registration in the exposure station upon the occurrence of each of said indications. 